The RNA-Binding Protein NANOS2 Is Required to Maintain Murine Spermatogonial Stem Cells

Abstract

Maintaining Germline Stem Cells: Spermatogonial stem cell pools in postnatal testes have to be maintained to continuously generate spermatozoa. It has been difficult to identify these stem cells in vivo, because of their small numbers and lack of appropriate molecular markers, but now Sada et al. (p. 1394 ) show that the RNA-binding protein NANOS2 is expressed in a small subset of spermatogonia that behave as self-renewing stem cells in intact testes. By a combinatorial use of loss- and gain-of-function studies, NANOS2 was found to be essential for the maintenance of the immature state of spermatogonial stem cells by supporting their self-renewing properties and by suppressing differentiation.